This invention relates to disc drives, and more particularly, to a disc drive PCB with flexible connectors.
Disc drive machines record and reproduce information stored on a recording media. Conventional Winchester-type disc drives include a plurality of vertically-aligned, rotating information storage discs, each having at least one associated magnetic head that is enclosed inside a sealed enclosure (also known as HDA or Head disc assembly) and adapted to transfer information between the disc and an external computer system. The information storage discs are journaled about a spindle motor assembly capable of rotating the discs at high speeds. The heads are carried by a plurality of vertically-aligned, elongated flexure arms that in turn are carried by a head positioner assembly. The head positioner assembly is adapted to move the heads back and forth in unison across the face of the vertically-aligned discs. The head positioner assemblies are traditionally either rotationally mounted, or take the form of a carriage that is free to move back and forth along a single axis. In either case, the head positioner assembly is adapted to precisely position the heads relative to the magnetic information storage discs.
The spindle motor assembly includes a rotatable spindle hub that is carried by a fixed spindle shaft securely mounted to the housing. In the alternative, the rotatable spindle hub may be carried by a rotatable spindle shaft, rotatably mounted to the housing. A plurality of information storage discs are journaled about the spindle hub. Spacer discs are provided between adjacent information storage discs. The vertically aligned information storage discs are clamped to the spindle hub by a disc clamp secured by a plurality of screws.
The electrical signals to and from the heads are carried by a plurality of electrical conductors to a preamplifier circuit. Amplified signals from the preamplifier circuit are made available to a printed circuit board located external to the sealed enclosure using a connector block mounted on the sealed enclosure. In addition, connector blocks mounted on the sealed enclosure are used to receive electrical signals to the positioner motor as well as the spindle motor from the printed circuit board. Complementary connector blocks mounted on the printed circuit board mate with the connector blocks mounted on the sealed enclosure, completing the electrical connections to the printed circuit board.
In U.S. Pat. No. 5,357,386 issued to Haidari et. al on Oct. 18, 1994 and currently assigned to Seagate Technology, Inc., Haidari et. al., disclose a disc drive with two connectors mounted to the base of the HDA casing and a circuit board with complementary connectors which mate with the connectors mounted to the base of the HDA casing, the teachings of which is fully incorporated by reference.
Disc drives are manufactured in high volumes. While the physical size of the disc drives have become smaller, the amount of data stored in a disc drive has increased. Further, there is a need to design disc drives for ease of manufacture and assembly, with minimal manufacturing steps and alignment procedures. The assembly of sealed enclosure takes place in a clean room environment, while the assembly of the printed circuit board takes place outside a clean room environment. As the physical size of the printed circuit board and the sealed enclosure decrease, need to precisely position the connector blocks on the printed circuit board and the connector blocks on the sealed enclosure become critical. Any manufacturing deviations in locating the connector blocks on the sealed enclosure or the printed circuit board will not precisely align the connector blocks, resulting in manufacturing defects and rework. For example, if the disc drive has two pairs of connector blocks as taught by Haidari et. al., and one of the connector blocks either on the printed circuit board or the sealed enclosure is not properly positioned, the connector blocks will not align properly for mating, causing manufacturing defect. In order to minimize manufacturing defects, the manufacturing assembly tolerance and component tolerances have to be specified with minimal allowable deviations, thereby increasing the cost of the assembly process and component prices. Further, as the physical size of the disc drive reduces, allowable deviations are further reduced.
There is a need to minimize the impact of any misaligned connector blocks in the sealed enclosure or the printed circuit board.
There is a need to allow for reasonable manufacturing deviations, without resulting in manufacturing defect.
There is a need to use component specifications allowing for reasonable deviations in dimensions, resulting in a lower cost component.
There is a need to provide for connector blocks on the printed circuit board which easily align and mate with corresponding connector blocks in the sealed enclosure, without requiring any rework.